// SPDX-License-Identifier: GPL-2.0-or-later /* AFS filesystem file handling * * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/fs.h> #include <linux/pagemap.h> #include <linux/writeback.h> #include <linux/gfp.h> #include <linux/task_io_accounting_ops.h> #include <linux/mm.h> #include <linux/swap.h> #include <linux/netfs.h> #include <trace/events/netfs.h> #include "internal.h" static int afs_file_mmap(struct file *file, struct vm_area_struct *vma); static int afs_symlink_read_folio(struct file *file, struct folio *folio); static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter); static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags); static void afs_vm_open(struct vm_area_struct *area); static void afs_vm_close(struct vm_area_struct *area); static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff); const struct file_operations afs_file_operations = { .open = afs_open, .release = afs_release, .llseek = generic_file_llseek, .read_iter = afs_file_read_iter, .write_iter = netfs_file_write_iter, .mmap = afs_file_mmap, .splice_read = afs_file_splice_read, .splice_write = iter_file_splice_write, .fsync = afs_fsync, .lock = afs_lock, .flock = afs_flock, }; const struct inode_operations afs_file_inode_operations = { .getattr = afs_getattr, .setattr = afs_setattr, .permission = afs_permission, }; const struct address_space_operations afs_file_aops = { .direct_IO = noop_direct_IO, .read_folio = netfs_read_folio, .readahead = netfs_readahead, .dirty_folio = netfs_dirty_folio, .release_folio = netfs_release_folio, .invalidate_folio = netfs_invalidate_folio, .migrate_folio = filemap_migrate_folio, .writepages = afs_writepages, }; const struct address_space_operations afs_symlink_aops = { .read_folio = afs_symlink_read_folio, .release_folio = netfs_release_folio, .invalidate_folio = netfs_invalidate_folio, .migrate_folio = filemap_migrate_folio, }; static const struct vm_operations_struct afs_vm_ops = { .open = afs_vm_open, .close = afs_vm_close, .fault = filemap_fault, .map_pages = afs_vm_map_pages, .page_mkwrite = afs_page_mkwrite, }; /* * Discard a pin on a writeback key. */ void afs_put_wb_key(struct afs_wb_key *wbk) { if (wbk && refcount_dec_and_test(&wbk->usage)) { key_put(wbk->key); kfree(wbk); } } /* * Cache key for writeback. */ int afs_cache_wb_key(struct afs_vnode *vnode, struct afs_file *af) { struct afs_wb_key *wbk, *p; wbk = kzalloc(sizeof(struct afs_wb_key), GFP_KERNEL); if (!wbk) return -ENOMEM; refcount_set(&wbk->usage, 2); wbk->key = af->key; spin_lock(&vnode->wb_lock); list_for_each_entry(p, &vnode->wb_keys, vnode_link) { if (p->key == wbk->key) goto found; } key_get(wbk->key); list_add_tail(&wbk->vnode_link, &vnode->wb_keys); spin_unlock(&vnode->wb_lock); af->wb = wbk; return 0; found: refcount_inc(&p->usage); spin_unlock(&vnode->wb_lock); af->wb = p; kfree(wbk); return 0; } /* * open an AFS file or directory and attach a key to it */ int afs_open(struct inode *inode, struct file *file) { struct afs_vnode *vnode = AFS_FS_I(inode); struct afs_file *af; struct key *key; int ret; _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode); key = afs_request_key(vnode->volume->cell); if (IS_ERR(key)) { ret = PTR_ERR(key); goto error; } af = kzalloc(sizeof(*af), GFP_KERNEL); if (!af) { ret = -ENOMEM; goto error_key; } af->key = key; ret = afs_validate(vnode, key); if (ret < 0) goto error_af; if (file->f_mode & FMODE_WRITE) { ret = afs_cache_wb_key(vnode, af); if (ret < 0) goto error_af; } if (file->f_flags & O_TRUNC) set_bit(AFS_VNODE_NEW_CONTENT, &vnode->flags); fscache_use_cookie(afs_vnode_cache(vnode), file->f_mode & FMODE_WRITE); file->private_data = af; _leave(" = 0"); return 0; error_af: kfree(af); error_key: key_put(key); error: _leave(" = %d", ret); return ret; } /* * release an AFS file or directory and discard its key */ int afs_release(struct inode *inode, struct file *file) { struct afs_vnode_cache_aux aux; struct afs_vnode *vnode = AFS_FS_I(inode); struct afs_file *af = file->private_data; loff_t i_size; int ret = 0; _enter("{%llx:%llu},", vnode->fid.vid, vnode->fid.vnode); if ((file->f_mode & FMODE_WRITE)) ret = vfs_fsync(file, 0); file->private_data = NULL; if (af->wb) afs_put_wb_key(af->wb); if ((file->f_mode & FMODE_WRITE)) { i_size = i_size_read(&vnode->netfs.inode); afs_set_cache_aux(vnode, &aux); fscache_unuse_cookie(afs_vnode_cache(vnode), &aux, &i_size); } else { fscache_unuse_cookie(afs_vnode_cache(vnode), NULL, NULL); } key_put(af->key); kfree(af); afs_prune_wb_keys(vnode); _leave(" = %d", ret); return ret; } /* * Allocate a new read record. */ struct afs_read *afs_alloc_read(gfp_t gfp) { struct afs_read *req; req = kzalloc(sizeof(struct afs_read), gfp); if (req) refcount_set(&req->usage, 1); return req; } /* * Dispose of a ref to a read record. */ void afs_put_read(struct afs_read *req) { if (refcount_dec_and_test(&req->usage)) { if (req->cleanup) req->cleanup(req); key_put(req->key); kfree(req); } } static void afs_fetch_data_notify(struct afs_operation *op) { struct afs_read *req = op->fetch.req; struct netfs_io_subrequest *subreq = req->subreq; int error = afs_op_error(op); req->error = error; if (subreq) { subreq->rreq->i_size = req->file_size; if (req->pos + req->actual_len >= req->file_size) __set_bit(NETFS_SREQ_HIT_EOF, &subreq->flags); netfs_read_subreq_terminated(subreq, error, false); req->subreq = NULL; } else if (req->done) { req->done(req); } } static void afs_fetch_data_success(struct afs_operation *op) { struct afs_vnode *vnode = op->file[0].vnode; _enter("op=%08x", op->debug_id); afs_vnode_commit_status(op, &op->file[0]); afs_stat_v(vnode, n_fetches); atomic_long_add(op->fetch.req->actual_len, &op->net->n_fetch_bytes); afs_fetch_data_notify(op); } static void afs_fetch_data_aborted(struct afs_operation *op) { afs_check_for_remote_deletion(op); afs_fetch_data_notify(op); } static void afs_fetch_data_put(struct afs_operation *op) { op->fetch.req->error = afs_op_error(op); afs_put_read(op->fetch.req); } static const struct afs_operation_ops afs_fetch_data_operation = { .issue_afs_rpc = afs_fs_fetch_data, .issue_yfs_rpc = yfs_fs_fetch_data, .success = afs_fetch_data_success, .aborted = afs_fetch_data_aborted, .failed = afs_fetch_data_notify, .put = afs_fetch_data_put, }; /* * Fetch file data from the volume. */ int afs_fetch_data(struct afs_vnode *vnode, struct afs_read *req) { struct afs_operation *op; _enter("%s{%llx:%llu.%u},%x,,,", vnode->volume->name, vnode->fid.vid, vnode->fid.vnode, vnode->fid.unique, key_serial(req->key)); op = afs_alloc_operation(req->key, vnode->volume); if (IS_ERR(op)) { if (req->subreq) netfs_read_subreq_terminated(req->subreq, PTR_ERR(op), false); return PTR_ERR(op); } afs_op_set_vnode(op, 0, vnode); op->fetch.req = afs_get_read(req); op->ops = &afs_fetch_data_operation; return afs_do_sync_operation(op); } static void afs_read_worker(struct work_struct *work) { struct netfs_io_subrequest *subreq = container_of(work, struct netfs_io_subrequest, work); struct afs_vnode *vnode = AFS_FS_I(subreq->rreq->inode); struct afs_read *fsreq; fsreq = afs_alloc_read(GFP_NOFS); if (!fsreq) return netfs_read_subreq_terminated(subreq, -ENOMEM, false); fsreq->subreq = subreq; fsreq->pos = subreq->start + subreq->transferred; fsreq->len = subreq->len - subreq->transferred; fsreq->key = key_get(subreq->rreq->netfs_priv); fsreq->vnode = vnode; fsreq->iter = &subreq->io_iter; trace_netfs_sreq(subreq, netfs_sreq_trace_submit); afs_fetch_data(fsreq->vnode, fsreq); afs_put_read(fsreq); } static void afs_issue_read(struct netfs_io_subrequest *subreq) { INIT_WORK(&subreq->work, afs_read_worker); queue_work(system_long_wq, &subreq->work); } static int afs_symlink_read_folio(struct file *file, struct folio *folio) { struct afs_vnode *vnode = AFS_FS_I(folio->mapping->host); struct afs_read *fsreq; int ret; fsreq = afs_alloc_read(GFP_NOFS); if (!fsreq) return -ENOMEM; fsreq->pos = folio_pos(folio); fsreq->len = folio_size(folio); fsreq->vnode = vnode; fsreq->iter = &fsreq->def_iter; iov_iter_xarray(&fsreq->def_iter, ITER_DEST, &folio->mapping->i_pages, fsreq->pos, fsreq->len); ret = afs_fetch_data(fsreq->vnode, fsreq); if (ret == 0) folio_mark_uptodate(folio); folio_unlock(folio); return ret; } static int afs_init_request(struct netfs_io_request *rreq, struct file *file) { if (file) rreq->netfs_priv = key_get(afs_file_key(file)); rreq->rsize = 256 * 1024; rreq->wsize = 256 * 1024 * 1024; return 0; } static int afs_check_write_begin(struct file *file, loff_t pos, unsigned len, struct folio **foliop, void **_fsdata) { struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); return test_bit(AFS_VNODE_DELETED, &vnode->flags) ? -ESTALE : 0; } static void afs_free_request(struct netfs_io_request *rreq) { key_put(rreq->netfs_priv); afs_put_wb_key(rreq->netfs_priv2); } static void afs_update_i_size(struct inode *inode, loff_t new_i_size) { struct afs_vnode *vnode = AFS_FS_I(inode); loff_t i_size; write_seqlock(&vnode->cb_lock); i_size = i_size_read(&vnode->netfs.inode); if (new_i_size > i_size) { i_size_write(&vnode->netfs.inode, new_i_size); inode_set_bytes(&vnode->netfs.inode, new_i_size); } write_sequnlock(&vnode->cb_lock); fscache_update_cookie(afs_vnode_cache(vnode), NULL, &new_i_size); } static void afs_netfs_invalidate_cache(struct netfs_io_request *wreq) { struct afs_vnode *vnode = AFS_FS_I(wreq->inode); afs_invalidate_cache(vnode, 0); } const struct netfs_request_ops afs_req_ops = { .init_request = afs_init_request, .free_request = afs_free_request, .check_write_begin = afs_check_write_begin, .issue_read = afs_issue_read, .update_i_size = afs_update_i_size, .invalidate_cache = afs_netfs_invalidate_cache, .begin_writeback = afs_begin_writeback, .prepare_write = afs_prepare_write, .issue_write = afs_issue_write, .retry_request = afs_retry_request, }; static void afs_add_open_mmap(struct afs_vnode *vnode) { if (atomic_inc_return(&vnode->cb_nr_mmap) == 1) { down_write(&vnode->volume->open_mmaps_lock); if (list_empty(&vnode->cb_mmap_link)) list_add_tail(&vnode->cb_mmap_link, &vnode->volume->open_mmaps); up_write(&vnode->volume->open_mmaps_lock); } } static void afs_drop_open_mmap(struct afs_vnode *vnode) { if (atomic_add_unless(&vnode->cb_nr_mmap, -1, 1)) return; down_write(&vnode->volume->open_mmaps_lock); read_seqlock_excl(&vnode->cb_lock); // the only place where ->cb_nr_mmap may hit 0 // see __afs_break_callback() for the other side... if (atomic_dec_and_test(&vnode->cb_nr_mmap)) list_del_init(&vnode->cb_mmap_link); read_sequnlock_excl(&vnode->cb_lock); up_write(&vnode->volume->open_mmaps_lock); flush_work(&vnode->cb_work); } /* * Handle setting up a memory mapping on an AFS file. */ static int afs_file_mmap(struct file *file, struct vm_area_struct *vma) { struct afs_vnode *vnode = AFS_FS_I(file_inode(file)); int ret; afs_add_open_mmap(vnode); ret = generic_file_mmap(file, vma); if (ret == 0) vma->vm_ops = &afs_vm_ops; else afs_drop_open_mmap(vnode); return ret; } static void afs_vm_open(struct vm_area_struct *vma) { afs_add_open_mmap(AFS_FS_I(file_inode(vma->vm_file))); } static void afs_vm_close(struct vm_area_struct *vma) { afs_drop_open_mmap(AFS_FS_I(file_inode(vma->vm_file))); } static vm_fault_t afs_vm_map_pages(struct vm_fault *vmf, pgoff_t start_pgoff, pgoff_t end_pgoff) { struct afs_vnode *vnode = AFS_FS_I(file_inode(vmf->vma->vm_file)); if (afs_check_validity(vnode)) return filemap_map_pages(vmf, start_pgoff, end_pgoff); return 0; } static ssize_t afs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) { struct inode *inode = file_inode(iocb->ki_filp); struct afs_vnode *vnode = AFS_FS_I(inode); struct afs_file *af = iocb->ki_filp->private_data; ssize_t ret; if (iocb->ki_flags & IOCB_DIRECT) return netfs_unbuffered_read_iter(iocb, iter); ret = netfs_start_io_read(inode); if (ret < 0) return ret; ret = afs_validate(vnode, af->key); if (ret == 0) ret = filemap_read(iocb, iter, 0); netfs_end_io_read(inode); return ret; } static ssize_t afs_file_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) { struct inode *inode = file_inode(in); struct afs_vnode *vnode = AFS_FS_I(inode); struct afs_file *af = in->private_data; ssize_t ret; ret = netfs_start_io_read(inode); if (ret < 0) return ret; ret = afs_validate(vnode, af->key); if (ret == 0) ret = filemap_splice_read(in, ppos, pipe, len, flags); netfs_end_io_read(inode); return ret; }